The contacts on the jacks may corrode if they are not excercised regularly. For instance, if you leave an effect unit plugged in the F-1X effects loop all the time, it is not excercised. Likewise, if you never use the effects loop, the same is true. Not all jacks are affected.
If you hear distortion or experience a loss of signal, try this simple cleaning routine first:
Plug and unplug any 1/4 connector to the jack 20-30 times. This will clean away any corrosion. Spray-on contact cleaners are not effective in this instance.
For the F-1X, excercise the effects return jack on the rear panel.
You can decide to excercise regularly, or just wait until you hear the recognizable problem and address it at that time.
If you have time for a more elaborate cleaning, here is another method contributed by Dan Brasier:
1. Cut a clean business card lengthwise into strips about 5 to 7 mm wide (about 1/4 inch). Keep these clean and handy. White works best as you can see what comes off the contact. (Unplug power cable first!)
2. Approach the offending switching jack CAREFULLY with the card strip hidden in your hand. Don't let the Jack see it until it is too late and it can't run away. Be careful and avoid psychological trauma by speaking gently to the connector. Use soothing tones and tell it how much better it will feel when it's clean.
3. Separate the contacts with a small (non scratching) item like a toothpick. Place the strip of paper between the switch leaves, and keep it well-centered.
4. Hold the leaves together with needlenose pliers or fingers, firmly but not too tightly.
5. Draw the paper strip out straight and slowly, and see what comes off onto the paper. (check both sides!) If it's dirty, start with a new piece and repeat until it's clean. Continue to keep a calm manner to avoid stressing the connector. Compliment it if necessary. Most like to hear what a low resistance they have.
6. Check and adjust the tension and travel on the contact when finished, by inserting a 1/4 male plug in the socket and observing the way the contact slides as it is actuated and deactuated. Too much tension is as bad as too little!
